Oxygen scavenging solutions for reducing corrosion by heat stable amine salts

Abstract

The formation of amine or glycol degradation products in solutions used to remove acid gases or water from hydrocarbon or inert streams is reduced by adding to the solution an oxygen scavenger in which the effective component is an oxime of the formula: ##STR1## Mixed with a quinone promotor in which R.sub.1 and R.sub.2 are the same or different and are selected from hydrogen or lower alkyl groups of one to six carbon atoms. The addition of the quinone promotor increases the reactivity with oxygen at lower temperatures. The compound may also be as a corrosion inhibitor in gas treating or processing equipment.

Claims

1. A method of reducing the formation of amine salts, in an alkanolamine solution for treating light hydrocarbon or gas, wherein said amine salts are formed by the reaction of the solution with carboxylic acids or sulfates formed from reactions of the alkanolamine with oxygen or H.sub.2 S with oxygen comprising reacting an oxime with the oxygen, in the presence of a quinone, by adding to the solution from 0.001 to 50,000 ppm an oxime of the formula ##STR5## in which R.sub.1 and R.sub.2 are the same or different and are selected from hydrogen or lower alkyl groups of one to six carbon atoms.

2. The method in claim 1 wherein the oxime is selected from a group consisting of methylethylketoxime, acetaldoxime, butyraldoxime, and propionaldoxime.

3. The method according to claim 1 in which the oxime addition to said solution is monitored by relating the oxygen concentration in at least one of the hydrocarbon feed and makeup water to the oxime injection rate and dosage level.

4. The method according to claim 1 in which the oxime addition to said solution is monitored by relating dissolved oxygen content of the solution to the oxime injection rate and dosage level.

5. The method according to claim 1 in which the quinone is added to said solution in from 0.001 to 50,000 ppm concentration in conjunction with the oxime to improve the oxygen reaction with the oxime at lower temperatures.

6. The method according to claim 5 in which the quinone is hydroquinone.

7. The method according to claim 5 in which the oxime and quinone addition to the alkanolamine solution is monitored by relating the oxygen concentration in at least one of the hydrocarbon feed and makeup water to the oxime injection rate and dosage level.

8. The method according to claim 5 in which the oxime and quinone addition to the alkanolamine solution is monitored by relating dissolved oxygen content of the solution to the oxime and quinone injection rate and dosage level.

9. The method of claim 1 wherein the alkanolamine is selected from a group consisting of monoethanolamine, diethanolamine, methyldiethanolamine, triethanolamine, methlymonoethanolamine, and diglycolamine.

10. The method of claim 1 in which the alkanolamine is comprised of mixtures of two or more alkanolamines or an alkanolamine and a physical absorbent comprising piperzine or sulfolane.

11. The method of claim 8 in which the solution includes an alkanolamine comprised of mixture of the two or more alkanolamines or an alkanolamine and a physical absorbent comprising piperzine or sulfolane.

12. A method of removing reaction products of alkanolamine and oxygen in an amine solution for treating light hydrocarbons or gas by filtering the alkanolamine solution through activated carbon.

13. A method of removing reaction products of both oxime and quinone in an alkanolamine solution for treating light hydrocarbons or gas by filtering the alkanolamine solution through activated carbon.

14. A method according to claim 13 in which the alkanolamine solution passes in a stream through an amine regenerator reflux device, and the carbon filtration is performed on the amine regenerator reflux stream.